Torque release handtool

ABSTRACT

A torque tool having a spring bar and plunger normally positioned in axial alignment with a cylindrical roller seated therebetween in opposing channels formed in the ends of the spring bar and plunger whereupon a predetermined torque being applied on said spring bar the roller is caused to roll up diagonally opposite vertical walls of the mating channels. This movement allows the bar limited relative movement with respect to the plunger, the bar colliding with the inner wall of the tubular housing surrounding the spring bar and plunger to produce an audible warning sound.

United States Patentllllllllllllllllllllllzwill!1/1/1111IIIIlllllllll/IIIIIIl/Il/111111Ill/n10,111101 o 3,140,623 7/1964 Van Hoose 81/52.4 3,018,677 1/1962 Mutolo et al.81/52.4 3,016,773 1/1962 Woods 8l/52.4

Primary Examiner.lames L. Jones, Jr. Attorney-Barlow and BarlowABSTRACT: A torque tool having a spring bar and plunger normallypositioned in axial alignment with a cylindrical roller seatedtherebetween in opposing channels formed in the ends of the spring barand plunger whereupon a predetermined torque being applied on saidspring bar the roller is caused to roll up diagonally opposite verticalwalls of the mating channels. This movement allows the bar limitedrelative movement with respect to the plunger, the bar colliding withthe inner wall of the tubular housing surrounding the spring bar andplunger to produce an audible warning sound.

PATENTEH JAM 1 m2 INVENTOR SULO A. AIJALA ATTORNEYS TORQUE RELEASEHANDTOOL BACKGROUND OF THE INVENTION This invention relates toimprovements in .torque applying tools that produce an audible warningsignal upon the application of a predetermined torque on the work.

The problems of torque-applying tools in the past have resulted from awearing away of the surfaces of the recesses in the adjacent ends of thespring arm and plunger members and also a wearing away of portions ofthe essential surface configuration of the connecting membertherebetween. This results in the torque-applying tool producing itsaudible signal at a torque force not in agreement with the setting onthe housing ofthe tool.

Also the wearing away of the surfaces on the connecting member and thesurfaces in the recesses at the ends of the plunger and spring arm varythe frictional resistances between the moving members during theirsliding or rotating motion. These varying frictional resistances effectunavoidable inaccuracies with regard to the amount of torque required incausing the tool to produce its audible warning.

Additional problems have resulted where the connecting member rotatesout of a recess in the plunger or spring arm and damages its surroundingsurface by making Brinnel indentations.

SUMMARY OF THE INVENTION The torque-applying tool has a spring bartrough which the torque is transmitted to the work. The spring bar has alimited lateral movement with respect to the body of the tool and isresiliently coupled to the means through which the torque is applied onthe spring bar. The resilient coupling includes a slidablespring-pressed plunger which is connected to the spring bar by means ofcylindrical roller which normally seats in concave recesses formed inthe ends of said plunger and spring bar. The recesses are adjacent eachother and are in axial alignment with the roller held in position byspring bias on said plunger.

When a torque is applied on the spring bar sufficient to overcome thespring pressure on said plunger, the spring will yield and allow thespring bar to move laterally causing the cylindrical roller to roll upout of the bottom of each of the recesses to a tripped position. Thedistance of lateral movement of the spring bar is limited by itsstriking the inner wall of the tools tubular housing. The audible soundproduced tells the user of the tool that the desired torque has beenapplied. In the tripped position the axes of the spring bar and plungerare out of alignment and the roller maintains line contact throughoutits length with diagonally opposite top edges of the recesses on therespective plunger and spring arm. Upon the torque force being removed,the spring bar will return to normal and the roller returns to itsseated position in the respective recesses.

One of the objects of the invention is to provide constant line contactalong the diametrically opposite sides of the con necting member withtwo of the opposing top linear edges of the recesses of the spring barand plunger respectively when the spring bar is in its tripped position.

Another object of the invention is to provide a tool of the abovecharacter wherein the free member connecting the plunger to the springbar will always return to its initial seated position when the torque isreleased.

Another object of the invention is to provide a free connecting memberof such a configuration so as to gain a more sensitive relationshipbetween the torque applied to the tool handle and the force transmittedto the free connecting member which causes the connecting member totravel from its seated position.

Also an object of the invention is to provide a tool of the abovecharacter which allows for corrections to be made between the freeconnecting member and its seated recess to maintain the necessarytolerances.

A further object of the invention is to provide a free connecting memberrestricted in its movement such that it doesn't produce surfaceindentations upon the surface surrounding the recess.

Another object of the invention is to provide a torque tool whose freeconnecting member is of such a configuration as to prevent, uponrepeated usage. the wearing away of the bottom surfaces of the recessesand also wearing away of the essential contact surfaces of the freeconnecting member which have formerly produced inaccuracies as to theamount of actual torque being applied.

Also an object of the invention is to provide a free connecting memberof such a configuration that there is reduced frictional resistancebetween the free member and the wall surfaces of the recesses as theymove relative to each other which results in a more precise measurementof the release torque.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of the torque tool;

FIG. 2 is a longitudinal sectional view taken along a horizontal planethrough the center of the tool as viewed from beneath the tool;

FIG. 3 is a fragmental elevational view of the adjacent ends of thespring bar and the plunger with a roller member in its resting position;

FIG. 4 is a fragmental elevational view of the roller member in itstripped position;

FIG. 5 is a fragmental elevational view partly in section of analternative embodiment having an adjusting screw in both the plunger andthe spring bar to vary the depth of the channel; and

FIG. 6 is a fragmental elevational view of an alternative embodimenthaving shims to reduce the depth of the channel.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to FIGS. 1 and 2,the number 10 designates the torque applying tool. The elongated tubularhousing 12 has a flattened and horizontally slotted end portionproviding spaced parallel walls 14 on the top and bottom of the housing. The other end of the tubular housing is externally screw threaded asat 16. The spring bar 18 has a circular head 20 which is of a thicknesssubstantially the distance between the top and bottom walls 14 and ispositioned therebetween. The circular head of the bar 18 is pivotallysecured in position by a pivot pin 19 which passes through circularholes in the top and bottom walls 14 with the mid portion 24 of the pinbeing of rectangular cross section which extends through a similarlyshaped opening in the circular head 20. A C-clamp 26 secures the top ofthe pivot pin 19 to prevent the pin from dropping out through the bottomwall 14. Thus the head 20 and the pivot pin are secured to each other tobe turned in unison; while at either side of this rectangular sectionthe pin is cylindrical and rotatably mounted in the walls 14. The pivotpin would have a work engaging projection of rectangular cross sectionat its lowermost length.

An antifriction bearing 30, which in the present embodiment is in theform of a sleeve 32, is inserted in the other end of the housing. Aplurality of circular rows of openings extend through the walls of thesleeve and ball bearings 34 are positioned in the said openings. Theball bearings are of a diameter slightly larger than the wall thicknessof the sleeve and will engage the walls of the bore 36 of the housing 12and also project slightly within the bore 38 of the sleeve 32. A plunger40 extends through the bore 38 and slidably engages said ball bearingsand is provided with flange 42 to limit the sleeve travel toward thespring. At one end of the plunger a cap 44 having a flange 46 isslidingly engaged over the tip of the cap with ball bearing 48therebetween.

The spring bar with its shank 22 normally extend in axial alignment withthe plunger 40, their two ends being in juxtaposition. The adjacent endsof the shank and plunger have opposing channels 50 and 52 respectivelywith a free connecting member 54 therebetween. The shape of the channelsis rectangular and they extend across the entire diameter of theirrespective members. Connecting member 54 is the shape of a cylindricalroll and is positioned such that its top and bottom surfaces restagainst the bottom surfaces in the opposing rectangular channels and theconnecting member is maintained in this position by means of a springbias placed on the plunger as will now be described.

The tubular housing has a handle 60 screw threaded upon its open end.Protruding from the closed inner end of the bandle is a stem 62 overwhich one end of compression spring 64 slips. The other end of thespring slides over the end of cap 44 and abuts flange 46. Turning thehandle relative to the tubular housing will increase or decrease thetension of the spring on the plunger 40 depending upon the direction ofrotation of said handle.

As can be seen from FIG. 3, in the normal resting position the freeconnecting member 54 will rest flat against the substantially parallelbottom walls of the channels and resiliently hold the spring bar andplunger connected together to move in unison upon turning of the handlein one or the other direction. It will also be seen that when resistanceof the work to be turned (which may be the tightening of a nut) isgreater than the frictional contact of the free member with the bottomwalls of the channels, the resistance of the shank 22 will cause arelative lateral movement between the housing and the shank. During thisrelative lateral movement the free connecting member will ride up two ofthe diagonally opposite walls of the opposing channels to the trippedposition shown in FIG. 4 and this movement causes the plunger to traveloutwardly against the bias of spring 64. Upon yielding of the resilientcoupling a relative lateral movement takes place between the housing andthe shank to provide an audible signal upon the shank striking the innerwall 36 of the housing. After the torque force applied to the handle isreleased, the spring pressure on the free member 54 acting thereonthrough the plunger 40 will roll the free member in the other directionto return the shank 22 to its normal rest position.

The tool is adjustable as to what torque will cause the shank to strikethe inner wall of the tubular housing. It is calibrated in torque unitsindicated by a scale 70 on the housing and datum lines 72 on the handlewhich may be moved into register therewith to indicate the torqueapplied to the work. Turning the handle to advance the same along thehousing 12 will increase the pressure of the spring 64. Turning thehandle to withdraw the same from the body will decrease the pressure ofthe spring 64. A locking ring 76 of ordinary design is provided forlocking the handle at any desired torque setting.

The problem of assembling torque tools are often aggravated by findingthat the tolerances of interconnecting pieces have not been maintained.This can be especially troublesome when the connecting member isoversized. FIG. discloses an alternative embodiment showing a shank 23having an adjustable screw formed in its bore that may be raised orlowered to vary the depth of the channel to provide a proper fit for theconnecting member 54. A like adjusting screw 43 is mounted in the boreof the plunger 41. Another method of solving this problem is to useshims 21 to reduce the depth of the channel as seen in FIG. 6.

I claim:

1. A torque tool which produces an audible warning signal comprising anelongated housing having a tubular bore open at one end, a work engagingmember pivotally mounted in the other end of the tubular housing, a barrigidly connected to said work engaging member and extending therefromthrough the bore of the tubular elongated housing, a plunger slidablymounted within the open end of the housing, the ends of said plunger andsaid bar adjacent each other each having a laterally extendingrectangular channel therein, said channels opening toward each other, acylindrical roller positioned between the ends of said plunger and saidbar resting with opposite longitudinal surfaces along the bottomsurfaces of the respective channels, whereupon a predetermined torquebeing applied on said bar the roller 15 caused to roll up diagonallyopposite vertical walls of the mating channels which movement allows thebar limited relative lateral movement with respect to said plunger, thebar colliding with the inner wall of the tubular housing to produce anaudible signal, and when the torque is released the roll returns to itsresting position.

2. A torque tool as recited in claim 1 wherein a shim is positioned inthe channel at the end of the spring bar beneath the roll.

3. A torque tool as recited in claim 1 wherein the bottom of the recessis at the end of the spring bar and provided with an adjusting screw toraise or lower the bottom surface of the channel.

4. A torque tool which produces an audible warning signal comprising anelongated housing having a tubular bore open at one end, a work engagingmember pivotally mounted in the other end of the tubular housing, a barrigidly connected to said work engaging member and extending therefromthrough the bore of the tubular elongated housing, a plunger slidablymounted within the open end of the housing, the ends of said plunger andsaid bar adjacent each other being connected by a laterally shiftablecoupling, a tubular handle having a closed end adjustably secured tosaid housing, a cup having a bottom wall embracing and guiding the endof the plunger which is distant from said bar, a ball bearing betweenthe said cup bottom wall and the adjacent end of said plunger, a flangefixed to said cup and of a diameter to engage the end of said housingand a spring acting between said flange and the closed 'end of saidhandle and urging said flange into engagement with the end of saidhousing, whereupon a predetermined torque being applied on said bar thecoupling is caused to allow the bar limited relative lateral movementwith respect to said plunger, the bar colliding with the inner wall ofthe tubular housing to produce an audible signal, and when the torque isreleased the coupling returns to its resting position.

5. A torque tool as in claim 4 wherein a stern on the closure end ofsaid handle extends into and guides the end of said spring.

1. A torque tool which produces an audible warning signal comprising an elongated housing having a tubular bore open at one end, a work engaging member pivotally mounted in the other end of the tubular housing, a bar rigidly connected to said work engaging member and extending therefrom through the bore of the tubular elongated housing, a plunger slidably mounted within the open end of the housing, the ends of said plunger and said bar adjacent each other each having a laterally extending rectangular channel therein, said channels opening toward each other, a cylindrical roller positioned between the ends of said plunger and said bar resting with opposite longitudinal surfaces along the bottom surfaces of the respective channels, whereupon a predetermined torque being applied on said bar the roller is caused to roll up diagonally opposite vertical walls of the mating channels which movement allows the bar limited relative lateral movement with respect to said plunger, the bar colliding with the inner wall of the tubular housing to produce an audible signal, and when the torque is released the roll returns to its resting position.
 2. A torque tool as recited in claim 1 wherein a shim is positioned in the channel at the end of the spring bar beneath the roll.
 3. A torque tool as recited in claim 1 wherein the bottom of the recess is at the end of the spring bar and provided with an adjusting screw to raise or lower the bottom surface of the channel.
 4. A torque tool which produces an audible warning signal comprising an elongated housing having a tubular bore open at one end, a work engaging member pivotally mounted in the other end of the tubular housing, a bar rigidly connected to said work engaging member and extending therefrom through the bore of the tubular elongated housing, a plunger slidably mounted within the open end of the housing, the ends of said plunger and said bar adjacent each other being connected by a laterally shiftable coupling, a tubular handle having a closed end adjustably secured to said housing, a cup having a bottom wall embracing and guiding the end of the plunger which is distant from said bar, a ball bearing between the said cup bottom wall and the adjacent end of said plunger, a flange fixed to said cup and of a diameter to engage the end of said housing and a spring acting between said flange and the closed end of said handle and urging said flange into engagement with the end of said housing, whereupon a predetermined torque being applied on said bar the coupling is caused to allow the bar limited relative lateral movement with respect to said plunger, the bar colliding with the inner wall of the tubular housing to produce an audible signal, and when the torque is released the coupling returns to its resting position.
 5. A torque tool as in claim 4 wherein a stem on the closure end of said handle extends into and guides the end of said spring. 